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Inflammation of the external auditory canal:
- Acute diffuse otitis externa: the most common form; an infectious process; usually bacterial; occasionally fungal (10%)
- Acute circumscribed otitis externa: synonymous with furuncle; associated with infection of the hair follicle, a superficial cellulitic form of otitis externa
- Chronic otitis externa: same as acute diffuse but of longer duration (>6 weeks)
- Eczematous otitis externa: may accompany typical atopic eczema or other primary skin conditions
- Necrotizing malignant otitis externa: an infection that extends into the deeper tissues adjacent to the canal; may include osteomyelitis and cellulitis; rare in children
- System(s) affected: skin/exocrine
- Synonym(s): swimmer’s ear
- Unknown; higher in the summer months and in warm, wet climates
- Predominant age: all ages
- Predominant sex: male = female
- Acute, chronic, and eczematous: common
- Necrotizing: uncommon
Etiology and Pathophysiology
- Acute diffuse otitis externa
- Traumatized external canal (e.g., from use of cotton swab)
- Bacterial infection (90%): Pseudomonas (67%), Staphylococcus, Streptococcus, gram-negative rods
- Fungal infection (10%): Aspergillus (90%), Candida, Phycomycetes, Rhizopus, Actinomyces, Penicillium
- Chronic otitis externa: bacterial infection: Pseudomonas
- Eczematous otitis externa (associated with primary skin disorder)
- Contact dermatitis
- Purulent otitis media
- Sensitivity to topical medications
- Necrotizing otitis externa
- Invasive bacterial infection: Pseudomonas, increasing incidence of methicillin-resistant Staphylococcus aureus (MRSA)
- Associated with immunosuppression
- Acute and chronic otitis externa
- Traumatization of external canal
- Hot, humid weather
- Hearing aid use
- Eczematous: primary skin disorder
- Necrotizing otitis externa in adults
- Advanced age
- Diabetes mellitus (DM)
- Debilitating disease
- Necrotizing otitis externa in children (rare)
- Diabetes insipidus
- Avoid prolonged exposure to moisture.
- Use preventive antiseptics (acidifying solutions with 2% acetic acid [white vinegar] diluted 50/50 with water or isopropyl alcohol or 2% acetic acid with aluminum acetate [less irritating]) after swimming and bathing.
- Treat predisposing skin conditions.
- Eliminate self-inflicted trauma to canal with cotton swabs and other foreign objects.
- Diagnose and treat underlying systemic conditions.
- Use ear plugs when swimming.